SigmaGauss2D

class sherpa.models.basic.SigmaGauss2D(name='sigmagauss2d')

Bases: sherpa.models.basic.Gauss2D

Two-dimensional gaussian function (varying sigma).

sigma_a

The sigma of the gaussian along the major axis.

sigma_b

The sigma of the gaussian along the minor axis.

xpos

The center of the gaussian on the x0 axis.

ypos

The center of the gaussian on the x1 axis.

theta

The angle of the major axis. It is in radians, measured counter-clockwise from the X0 axis (i.e. the line X1=0).

ampl

The amplitude refers to the maximum peak of the model.

See also

Gauss2D, NormGauss2D

Notes

The functional form of the model for points is:

f(x0,x1) = ampl * exp(-r(x0,x1)^2 / 2)

r(x0,x1)^2 = xoff(x0,x1)^2 + yoff(x0,x1)^2
             -------------   -------------
               sigma_a^2       sigma_b^2

xoff(x0,x1) = (x0 - xpos) * cos(theta) + (x1 - ypos) * sin(theta)

yoff(x0,x1) = (x1 - ypos) * cos(theta) - (x0 - xpos) * sin(theta)

The grid version is evaluated by adaptive multidimensional integration scheme on hypercubes using cubature rules, based on code from HIntLib ([1]) and GSL ([2]).

References

[1]	HIntLib - High-dimensional Integration Library http://mint.sbg.ac.at/HIntLib/

[2]	GSL - GNU Scientific Library http://www.gnu.org/software/gsl/

Attributes Summary

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Summary

apply(outer, \*otherargs, \*\*otherkwargs)
calc(\*args, \*\*kwargs)
get_center()
guess(dep, \*args, \*\*kwargs)
reset()
set_center(xpos, ypos, \*args, \*\*kwargs)
startup()
teardown()

Attributes Documentation

thawedparhardmaxes

thawedparhardmins

thawedparmaxes

thawedparmins

thawedpars

Methods Documentation

apply(outer, *otherargs, **otherkwargs)

calc(*args, **kwargs)

get_center()

guess(dep, *args, **kwargs)

reset()

set_center(xpos, ypos, *args, **kwargs)

startup()

teardown()